A common surgical technique currently available is the complete replacement of a malfunctioning or damaged human heart valve with a prosthetic valve. While the mortality rate for such replacement has improved considerably over the last few years, certain dangers still exist. For example, there is a recognized incidence of failure of these operations due to the trauma occasioned by the replacement operation itself. For most prosthetic heart valves, the suturing of the valve in place requires an extended period of time during which extra-corporeal perfusion and coronary-pulmonary bypass is necessary.
Typically, the prosthetic heart valve is provided with a suture ring, generally made from a cloth material or some other biologically compatible material, which is used in suturing the heart valve in position within the heart. The valve is secured by sutures connecting the sewing ring to the tissue surrounding the valvular orifice. The surgeon or an assistant typically holds the prosthesis in position during the suturing operation, by use of a holding device which engages the body of the valve.
Once the prosthetic heart valve is in place, it sometimes becomes necessary to rotate or reposition the valve. This is generally accomplished by reattaching the holder to the valve and rotating the holder.
Reusable holding devices, although extensively used for holding the heart valve during the suturing procedure, all suffer from several problems. Thus, they require a considerable amount of time for the surgeon both to premount the prosthesis on them, and, if necessary, reattach the holder during the surgical procedure. These holders generally comprise complex mechanisms in which an advancing screw thread causes two or more fingers to spread apart and engage a surface of the prosthetic heart valve. Numerous turns of the screw mechanism are usually required, depending upon the size of the valve being mounted on the holder. The surgeon is also required to position the holder on the heart valve in the proper orientation, whether it be aortic or mitral. If the holder is attached to the valve incorrectly or in the improper orientation, valuable time is lost which increases the risk to the patient.
Furthermore, the reusable heart valve holders have to be cleaned and sterilized after each operation, adding to the expense of a very expensive operation. Moreover, after many uses, there is a danger that the holder will malfunction, damage the valve, or even completely fail. A broken-off piece of the holder could cause severe injury to the patient or death. At best, a serious time delay will result with further danger to the patient.
Various types of disposable holders are currently available which, because they are prepositioned on the heart valve prior to surgery, overcome many of the disadvantages of the prior art reusable holders. However, no known prior art holder provides the ease of removal and reattachment coupled with the inexpensive manufacturability of valve holders constructed in accordance with this invention.